Sickle bar elevator



Feb, 27, 195K) I R THOMAS I 2,496,6U8

SICKLE BAR ELEVATOR Filed March 29, 1948 INVENTOR. 6% Wm/Ms BY iatentedFeb. 7, 1950 UNITED SICKLE BAR ELEVATOR Roy R. Thomas, Spokane, Wash,assignor to Lyle GordanMcLean, Spokane, Wash.

Application March 29, 1948, Serial No. 17,737

Claims. (CI. 56-25) My present invention relates to an improved sicklebar elevator of the type adapted for use on tractor drawn and operatedsickle mowers.

Generally my elevator or lift mechanism comprises a gear cluster andclutch arrangement operable on the power shaft for the sickle bar todrive a worm gear shaft in a meshing sleeve on the sickle bar drive unitso that actuation of the clutch will rotate the worm gear shaft ineither selected direction to raise or lower the sickle bar.

In the accompanying drawings I have illustrated one complete example ofthe physical embodiment of my invention according to the best mode Ihave thus far devised but it will be understood that various changes andalterations may be made in the exemplified structure within the scope ofthe appended claims.

In the drawings:

Figure 1 is a top plan view of the sickle bar attachment for a tractorshowing the elevating mechanism of my invention.

Figure 2 is a longitudinal vertical sectional view through the elevator.

Figure 3 is a horizontal sectional view thereof.

Referring now to the drawings wherein I have illustrated the presentpreferred embodiment of my invention I use the frame portion 2 of atractor of suitable and conventional design having a wheel tire 4 andthe frame arm 6 supporting the sickle bar base 8.

A power takeoff unit It) includes a pulley l2 driving belts I4 and thesebelts in turn drive the pulley 16 on shaft l8 which is journaled inbrackets 20 on base 8. Pulley 22 and belts 24 drive pulley 26 and itsshaft, a part of the driving mechanism 28 for the shaft 30 whichreciprocates the sickle bar 32 on its support 34. The driving mechanism28 is pivotally mounted in the arms 36 and 38 of base 8 and it is thepurpose of my invention to mechanically raise or lower the sickle bar toelevate the bar from operating position or vice versa.

A housing 40 has collars 42 formed with bushings 44 journaled on shaftl8 and within the housing I provide thrust bearings 46 for the beveledgears 48 and 50 rotatable on shaft IR. A third beveled gear 52 mesheswith the gears 48 and 50 and has a thrust bearing 54 in the collar 56 ofhousing 40. The shaft 58 for the gear 52 is journaled in bushing 60 andat its outer end is formed with a helical oI' worm thread 62. Thisthreaded end meshes the interior worm thread 64 of sleeve 66 which ispivotally secured 2 a by pin 68 to bracket 10 on the drive mechanism 28.i To control the direction of rotation of gear 52 and shaft 58 I employa clutch collar on and keyed at H1 to shaft [8, and formed with anannular groove 14. The discs 16 and 18 have lugs or dogs 30 forenmeshing with the grooves 82 of the gears 48 and 50' selectively.

A shifting arm 84 has a ball 86 located in the groove 74 and pivoted at88 in the housing, and a link 90 is connected at 92 to the arm 84 sothat the operator of the tractor may by moving the link forward orbackward, shift the collar backward or forward to operatively connecteither gear 48 or 50 with the shaft l8 and. in turn rotate the gear 52and its shaft. The movement of the shaft 58 clockwise looking toward thethreaded end thereof will shorten the shaft and sleeve and raise themower bar, while counter-clockwise movement of the shaft will lengthenthe shaft and sleeve and lower the bar and support.

From the above description of the elevator of my invention it will beapparent that without effort on behalf of the operator the sickle barmay be raised or lowered at will merely by control of the clutch collarin the housing 40 utilizing the power in the shaft l8 from the usualpower take-off mechanism.

Having thus fully described my invention what I claim as new and desireto secure by Letters Patent is:

1. In a sickle bar elevator, the combination with a power take-off shaftfor a tractor and a pivotally mounted drive unit for the sickle bar, ofa gear cluster and housing journaled on the take-off shaft, clutch meansfor selectively operating the driven gear of the cluster, an elevatingshaft rigid with the said driven gear, and means connecting theelevating shaft and the drive unit to pivot the unit and the sickle bar.

2. In a sickle bar elevator, the combination with a power take-off shaftfor a tractor and a pivotally mounted drive unit for the sickle bar, ofa gear cluster and housing journaled on the take-off shaft, clutch meansfor selectively operating the driven gear of the cluster, an elevatingshaft rigid with the said driven gear, a worm thread on the elevatingshaft, and an interiorly threaded sleeve meshing with the worm threadand connected with the drive unit to pivot the unit and the sickle bar.

3. In a sickle bar elevator, the combination with a power take-off shaftfor a tractor and a pivotally mounted drive unit for the sickle bar, ofa gear cluster and housing journaled on the take-off shaft, clutch meansfor selectively operating the driven gear of the cluster, an elevatingshaft rigid with the said driven gear, and means connecting the shaftand drive unit whereby rotation of the shaft in one direction willshorten the connecting means and rotation of the shaft in the otherdirection will lengthen the connecting means.

4. In a sickle bar elevator for a mowing mar chine, the combination witha base frame, a sickle and its driving unit pivotally mounted on theframe, a driven operating shaft, and power transmission mechanismbetween said shaft and the driving unit, of an internally threadedsleeve pivotally mounted on the driving unit, a reversible screw barrotatably threaded in the sleeve, and manually controlled reversiblemeans coacting with and connecting the operating shaft and the screw barfor actuating the latter from the ,former.

5. In a sickle bar elevator for a mowing machine, the combination with abase frame, a sickle and its driving unit pivotally mounted "controlledmeans for said clutch.

ROY R. THOMAS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,343,732 Leopold June 15, 19202,299,841 Moyer Oct. 27, 1942' 2,329,881 Clapper Sept. 21, 1943

